The present invention relates to polishing and planarization of semiconductor wafers. More particularly, the present invention relates to a method and apparatus for linearly reciprocating a portion of a continuous polishing member to process a semiconductor wafer.
Chemical mechanical planarization/polishing (CMP) techniques are used to planarize and polish each layer of a semiconductor wafer. Available CMP systems, commonly called wafer polishers, often use a rotating wafer carrier that brings the wafer into contact with a polishing pad rotating in the plane of the wafer surface to be planarized. A chemical polishing agent or slurry containing microabrasives and surface modifying chemicals is applied to the polishing pad to polish the wafer. The wafer holder then presses the wafer against the rotating pad and is rotated to polish and planarize the wafer. Some available wafer polishers use orbital motion, or a linear belt, rather than a rotating surface to carry the polishing head. One challenge faced in polishing semiconductor wafers using a disposable polishing pad on the available wafer polishers is that these polishers typically need to be frequently stopped to replace the polishing member after a limited number of uses. Accordingly, there is a need for a method and system of performing CMP that addresses this issue.